title: pqqA is not required for biosynthesis of pyrroloquinoline quinone in Methylobacterium extorquens AM1.
abstract: Methylobacterium extorquens AM1 is a facultative methylotroph that oxidizes methanol via the pyrroloquinoline quinone (PQQ)-linked enzyme methanol dehydrogenase. In M. extorquens AM1 and other PQQ-synthesizing bacteria, several genes are involved in the synthesis of PQQ and one of these, pqqA, has been proposed to encode a peptide precursor of PQQ. In other PQQ-synthesizing bacteria, pqqA is required for PQQ production. In this study, it is shown that both deletion and insertion mutants of pqqA in M. extorquens AM1 grow normally on methanol and produce PQQ. The level of PQQ production is reduced in the insertion mutant, but it is sufficient to allow normal growth on methanol. These results suggest either that a different peptide in M. extorquens AM1 can substitute for PqqA in pqqA mutants, or that PqqA-like peptides may not be obligatory precursors of PQQ. In addition, it is shown that the methanol oxidation transcriptional regulator gene, mxbM, is required for normal methanol induction of PQQ synthesis.
authors.affiliation: Department of Chemical Engineering, University of Washington, Box 351750, Seattle, WA 98195, USA.
authors.forename: Hirohide
authors.initials: H
authors.lastname: Toyama
authors.affiliation: Department of Chemical Engineering, University of Washington, Box 351750, Seattle, WA 98195, USA.
authors.forename: Mary E
authors.initials: ME
authors.lastname: Lidstrom
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D002630:Chemotactic Factors / Q000096:biosynthesis; D017353:Gene Deletion; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D016946:Gram-Negative Aerobic Rods and Cocci / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D000432:Methanol / Q000378:metabolism; D016254:Mutagenesis, Insertional; D045542:PQQ Cofactor; D015363:Quinolones / Q000378:metabolism*; D011809:Quinones / Q000378:metabolism*; D011995:Recombination, Genetic; D015183:Restriction Mapping; D016415:Sequence Alignment
chemical_list: D001426:Bacterial Proteins; D002630:Chemotactic Factors; C095466:PqqA protein, Methylobacterium extorquens; D015363:Quinolones; D011809:Quinones; D045542:PQQ Cofactor; D000432:Methanol